Various piezoelectric motor designs are known in which a stator and rotor interact through pushers by friction. For example, in some conventional piezoelectric motor designs, a rotor and stator based on an annular piezoelement are provided, where the outer cylindrical surface is installed in a wave shell, on which a set of pushers are mounted. Improved reliability of such a motor is realized because the pushers are installed on a separate acoustic-wave conducting shell (wave shell) which is mounted on the piezoelement rather than fitted to slots cut directly into the relatively more fragile annular piezoelement. Also by matching the radial resonance frequency of the wave shell to the radial resonance frequency of the annular piezoelement an improvement in the energy efficiency of the system is achieved. Such a device is excited at the zero order radial mode of vibration of the annular piezoelement, which is considered most effective in terms of amplitude and the quality factor (Q factor) of the whole system.